RESUMO
OBJECTIVE: This study aims to evaluate the diagnostic performance of the Summated Xerostomia Inventory (SXI-ID) questionnaire in detecting xerostomia and salivary gland hypofunction (SGH). SUBJECTS AND METHODS: This diagnostic study first underwent a validity and reliability test. Participants were randomly sampled from the Geriatric Clinics of Dr. Hasan Sadikin Hospital, Bandung, Indonesia. The SXI-ID was generated through a forward-backward translation, after which its validity (item-total item correlations), internal consistency (Cronbach's alpha), and test-retest reliability (kappa statistic) were all assessed. The diagnostic performance of the SXI-ID in detecting SGH was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 60 participants (aged ≥60 years) were involved in this study, most of whom were female (75%). The internal consistency of the SXI-ID was acceptable (α = 0.823), and its test-retest reliability was perfect (K= 1.00). ROC analysis showed that an SXI-ID cut-off value > 11 could detect SGH with a sensitivity of 96.0%, a specificity of 100.0%, and an area under the curve of 0.985 (p < 0.001). CONCLUSIONS: The SXI-ID questionnaire is a valid and reliable tool to detect xerostomia and SGH in older Indonesians, and a score of 11 or above is useful to identify those with a low salivary flow.